• 조명전기설비학회논문지
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• 제24권7호
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• pp.20-25
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• 2010

With the diversification of distribution facilities, existing distributed generation can be subdivided into Microgrids, which are smaller units for application. These Microgrids, subdivided as such and connected to distribution systems, should operate under driving plans that will ensure their economic efficiency and, accordingly, the configuration of those distribution systems that include Microgrids should also be changed. The perception of the necessity to secure the economic efficiency of distribution systems is gradually increasing and studies intended to assess the economic efficiency of Microgrids and Smartgrids are ongoing. In this paper, the power generation capacity of an economically operative Microgrid was calculated using the MonteCarlo simulation, which is a method based on the probability theory considering the power generation cost of Microgrids linked with power supply systems and reverse sales costs, etc., and an optimum distribution systems was configured based on the results of these calculation.

• 산업공학
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• 제15권4호
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• pp.325-337
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• 2002

In this study we consider the problem of production planning of TFT-LCD(Thin Film Transistor - Liquid Crystal Display) production factory. Due to the complexities of the TFT-LCD production processes, it is difficult to schedule the production planning, and the study about automated scheduler is insufficient. In addition, the existing production method is a Push-System to raise the operation rate with expensive equipment, that has the problem to satisfy the due-date. This study presents an algorithm having a concept of Pull-System that satisfies the due-date and considers specialties of TFT-LCD production process. We make MPS(Master Production Schedule) according to the sales order, and present algorithms for scheduling about In/Out plan considering factory capacity, line balancing, material requirement, and inventory level of all Array, Cell, and Module processes. These algorithms are integrated as an automated production system, and we implement them in the actual TFT-LCD factory circumstance.

• 자원ㆍ환경경제연구
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• 제9권2호
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• pp.349-371
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• 2000

Data Envelopment Analysis model is a linear programming based technique for measuring the relative performance of organizational units where the presence of multiple inputs and outputs makes comparison difficult. A common measure for relative efficiency is weighted sum of outputs divided by weighted sum of inputs. DEA model allows each unit to adopt a set of weight that shows it in the most favorable light in comparison to the other unit. In this paper, we present the mathematical background and characteristics of DEA model, and give a short case study where we apply the DEA model to evaluate the relative efficiencies of 51 global electricity companies. The technical efficiency and scale efficiency are also to be investigated. Generating capacity and the number of employees are used for input data, and revenue, net profit and electricity sales are used for output data. We find that the companies with 100% relative efficiency are only 9 among 51 electricity companies. And the technical and scale efficiency of KEPCO is 98.7% and 78.89%, respectively. This means that the inefficiency of KEPCO is caused by the scale inefficiency. The analysis shows that the employees should be decreased by 15% at minimum to get the 100% efficiency. The result suggests that KEPCO needs the structural reform to improve the efficiency.

• 자원ㆍ환경경제연구
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• 제16권4호
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• pp.763-779
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• 2007

최근 고유가와 교토의정서의 발효에 따라 에너지 이용효율성 제고와 온실가스 배출삭감의 필요성이 증대되고 있는 상황에서 소형열병합 발전이 주목받고 있다. 본 연구는 열병합발전의 판매전력가격의 변동성으로 인해 미래수익이 불확실할 경우를 상정하여, 비가역적 성격의 열병합발전 설비투자에 대한 경제성 평가 모형을 제시한다. 이를 위해 실물옵션 기법을 이용하였다. 전력가격의 평균회귀성을 실증적으로 반영한 시설규모별 발전설비에 대한 모의실험 결과, 40Gcal 용량 이상의 발전설비에 대해 경제성이 보장되는 것으로 나왔다. 열병합발전의 경제성은 투자비용과 열수요 판매가격, 할인율에 영향을 받는 것으로 나타났다.

• 한국의상디자인학회지
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• 제17권3호
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• pp.149-158
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• 2015

More weight is given today to the role and capacity of fashion shopmasters who stand in direct contact with customers at department stores. The present study examines relationship between the stress factors and the job satisfaction by fashion shopmasters. The questionnaires was prepared 300 fashion shopmasters who work at fashion brand shops for ladies' formal and casual dress in department stores located in Chungcheong provincial areas from Aug. 5 to 23, 2013. Out of the distributed questionnaires, 270 were returned and 256 were put to the final analysis after excluding those that were replied unfaithfully. The second stage was to collected data underwent frequency analysis, factor analysis, reliability analysis and regression analysis to determine the effects of variables by using SPSS 18.0. Fashion shop masters are therefore requested to have exact understanding to their role as retail sales professionals, fashion advisers and experts of fashion shop management, to become well aware of their job in detail, to apply such knowledge to their practical job performance and to make personal efforts to promote their status as fashion shop masters.

• 수산경영론집
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• 제43권2호
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• pp.51-66
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• 2012

The purpose of this study is to present a new business performance model suitable for marin repair business. For this propose we have used survey datas gathered on several input and output factors from Marine engin repair companies Yeong-Do Gu. Gathering these the survey results we estimated the efficiency of each company through DEA method. The results of the analysis can be summarized as follows ; First, the result of the analysis showed 7 out of 24 DMU are not efficient companies. On the other hand 17 of them are efficient as the efficient output analyzes showed. Second, by analysing the results we could see significant differences between group companies, Ltd with a private companies with share on average efficiency in utilization. Third, two of the private companies are more effective and 6others were selected revisit and interview on the analysis. As a result inefficient DMU compared to efficient DMU and showed that they invest more on manpower in the field of sales and professional managers and techicians. Also, lots of effort devoted in order to standardize production by building capacity and environment management to improve welfare of the workers.

• 품질경영학회지
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• 제38권3호
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• pp.463-474
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• 2010

In this study, we evaluate the efficiency of Construction Industry using Data Envelopment Analysis(DEA). Since the Construction Industry has been traditionally operated through competition, it is important to measure the efficiency. In this paper, we empirically analyze the Efficiency of the 50 Korean Construction Industry. In detail, we used the scale of efficiency in order that efficiency cannot be affected by the total technical efficiency of each company and the scale of DMU by applying CCR or BBC model. Also, we analyzed the changes of measurement DEA model score. we adopted the basic DEA, RTS Region and MPSS(Most Productive Scale Size) method which are combined with efficiency measurement model in order to analyze the operational status. Furthermore, by complementing the shortfalls of the scale efficiency value of the DEA Model, RTS Region Model can be recommended to be appropriate in the evaluation of ideal input/output Quantity. In particular, input variables are total assets, construction capacity, the technical staff and output variables are sales volume, operating income. The result of RTS Region and MPSS shows that 9 DMUs of the efficiency frontier in the Construction Industry are analyzed to be relatively efficient DMUs, and 41 DMUs are analyzed to be inefficient DMUs, and finally inefficient DMUs are separated with Region 1 and Region 6.

• 한국분무공학회지
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• 제25권1호
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• pp.34-39
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• 2020

Automotive manufacturers are applying technologies for greenhouse gas reduction such as vehicle weight reduction, engine downsizing, direct injection technology, variable valves and transmission performance improvement to achieve the targets for enhanced greenhouse gas and fuel consumption efficiency. In this paper, compared and analyzed greenhouse emissions according to engine capacity, engine displacement, curb weight and sales volume of hybrid and internal combustion engine passenger vehicles. Hybrid emit 32~39% less greenhouse gas than internal combustion engines through the combined mode test method. Hybrid electric vehicle's curb weight was about 7% heavier on average for the same engine displacement, while greenhouse gas was about 36% lower. It was confirmed that in order to reduce the emission of pollutants of greenhouse gases as well as the air pollutants, it is necessary to expand the supply of eco-friendly vehicles.

• 수산경영론집
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• 제43권1호
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• pp.11-18
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• 2012

This study is aimed to estimate a dynamic productive efficiency by vessel of large purse seine fishery and analyze changes of them over times using a window/DEA method. In addition, based on estimation results, it aims to suggest production management implications for an viable development of fisheries. Results indicated that an annual efficiency change of large purse seine fishery was estimated at 0.77 for 2007~2008, 0.83 for 2008~2009, and 0.77 for 2009~2010, showing a decreasing trend. As returns on sales of vessels of large purse seine fishery showed a decreasing trend, the degree of efficiency of a vessel might be closely related to the fishing profitability. The Window/DEA method was used in this study to estimate the efficiencies of vessels for large purse seine fishery. This method is well known and widely used to analyze the dynamic efficiency and it can provide useful implications for management of input factors. As a limitation of this study, it was not able to provide detailed management ways to reduce inefficiencies. However, they can be investigated with data on managerial factor, human factor, distribution factors as a future study.

• 대한안전경영과학회지
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• 제4권1호
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• pp.105-114
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• 2002

Nowadays, most companies seek after the greatest profit by means of offering the goods which consumers want timely and efficiently and minimizing the cost of inventory and distribution channel which amounts to the great portion of total cost. And according as EC(Electronic Commerce) market has increased rapidly, SCM(Supply Chain Management) for EC become one of the most important facts for companies, therefore this paper suggest SCM scheme which EC, especially B to C, is added to the existing commerce system. This paper uses internet for information integration of distribution channel which is away from one another and applies TOC(Theory of Constraint)'s DBR(Drum-Buffer-Rope) Scheduling for synchronization through the whole supply chain. It is possible to synchronize the whole supply chain by means of making the speed of manufacturing and distribution to be controlled by consumer's order which is received in distribution center, and inventory and loss of sales opportunities are minimized by constant. Buffer Management. If inventories in distribution center is short, then it needs to search CCR(Capacity Constraint Resource) in supply chain and to control the speed of manufacturing and distribution according to the ability of CCR. This paper applies PT(Partial Transshipment) strategy for Delivery from distribution center to store or cyber consumer. the strategy this paper suggests chooses neighbour area from area which each distribution center takes charge, and then makes product ordered by cyber consumer which lives in the chosen area to be delivered according to inventory of distribution center.